Command line to find prime factors up to about 50-digit
echo 2349975432075028306522249994659146745284026576085795466683757397081757781623192121173278642996005041765472451878912175009079450533017154820654147706637612424961011771240573394005426306906791429 | ecm -n -c 6335 43e6
Command line to find prime factors up to about 55-digit
echo 2349975432075028306522249994659146745284026576085795466683757397081757781623192121173278642996005041765472451878912175009079450533017154820654147706637612424961011771240573394005426306906791429 | ecm -n -c 17348 11e7
Command line to find prime factors up to about 60-digit
echo 2349975432075028306522249994659146745284026576085795466683757397081757781623192121173278642996005041765472451878912175009079450533017154820654147706637612424961011771240573394005426306906791429 | ecm -n -c 41882 26e7
Command line to find prime factors up to about 65-digit
echo 2349975432075028306522249994659146745284026576085795466683757397081757781623192121173278642996005041765472451878912175009079450533017154820654147706637612424961011771240573394005426306906791429 | ecm -n -c 69380 85e7